I am working on my graduation design project, and I am responsible for making the power supply circuit. It is a lower power source, and acts like a current source that can supply current in the range of 30 mA to 130 mA. My power supply circuit has a source impedance of 85 ohm. Our load, a microcontroller, can be modelled by a load between 15 ohm to about 200 ohm depending on current draw. At a load ~15 ohms, I only get about ~300 mV at the output. Is there a way to make my load seem larger so voltage division works in my favor? The two quick methods I thought don't seem to work to well: 1. Unity feedback buffer. This requires an op amp, which needs 15 V biasing rails. Since I am the power supply circuit already at a low voltage, I cannot properly bias the amplifier. 2. I can build more of my power supply circuit and put them in parallel to decrease the source impedance, but this can get expensive and may exceed our project's budget. Thanks for all the suggestions in advance!